1. Field of the Invention
The present invention relates to a roll staple in which staples are jointed in side by side and wound in a roll shape.
2. Description of the Prior Art
As for the roll staple of this kind, that is shown, for example, in FIG. 6 and FIG. 7 is well known. This roll staple 1 comprises a roll staple body 11 and pulling out tape 12. The roll staple body 11 is composed of a belt like sheet staple which is made of straight staples 10a adhered together with their sides parallely adjoining, and the sheet staple is rolled in a coil shape so as to form a through hole la along a center axis of the roll in order to form the roll staple. Herein, the roll staple is formed so that a leading end 11a of the sheet staple is positioned in an outer surface of the roll and trailing end 11b of the sheet staple is positioned in an inner surface of the roll, that is to say, the inner surface of the a through hole 1a. 
The pulling out tape 12 is attached removably on a portion near by the leading end 11a of roll staple body 11 by an adhesive material. The pulling out tape 12 is wound one round on the roll staple body 11 and a seizing portion 12a is mounted on its top end which is a free end of the tape 12.
The roll staple 1 which is composed as described above, is inserted and set in a staple cartridge (not shown) and then the pulling out tape 12 is pulled out from the staple cartridge, as a result only the roll staple body 11 is loaded on the staple cartridge. By pulling out of the pulling out tape 12, a state in which the leading end 11a of roll staple body 11 is set on a regulated position in the staple cartridge, is realized.
The staple cartridge is loaded on, for example, a motor operated stapler which is built in a copying machine. The motor operated stapler binds a pile of papers by means of a punching out of every staple 10a at leading end of sheet staple which is guided out from the roll staple body 11.
However, in the above described roll staple 1 of prior art, when a strong impact is applied against the roll staple body 11, for example because the roll staple is fallen onto a floor, there may be a case that the through hole 1a is deformed into oval shape as shown in FIG. 8. If the through hole 1a has been deformed as such, there may be case that portions near a trailing end 11b of the roll staple body 11 is broken, for example, by having a pressure in vertical direction in L shape or as irregularly overlapping. And if such kind of breakage is happened, there may be a case that the broken portion blocks, for example, a guide path of the above described staple cartridge, which guides the sheet of staples from roll staple body 11.
The purpose of the invention is to provide a roll staple in which happening of broken sheet staple at the trailing end portion of sheet staple of the roll staple body 11 located in the through hole.
The present invention has a feature that a roll staple characterized by comprising a roll staple body which is made of a sheet staple formed by a large number of straight staples jointed parallely, and wound so as to make a through hole at the portion of central axis, and a core material which is inserted into the through hole of the roll staple body.